Flexible region based sample adaptive offset (SAO) and adaptive loop filter (ALF)

Abstract

A method for in-loop filtering in a video encoder is provided that includes determining filter parameters for each filtering region of a plurality of filtering regions of a reconstructed picture, applying in-loop filtering to each filtering region according to the filter parameters determined for the filtering region, and signaling the filter parameters for each filtering region in an encoded video bit stream, wherein the filter parameters for each filtering region are signaled after encoded data of a final largest coding unit (LCU) in the filtering region, wherein the in-loop filtering is selected from a group consisting of adaptive loop filtering and sample adaptive offset filtering.

What is claimed is: 
     
       1. A method comprising:
 receiving a bitstream representing a picture, wherein the picture includes a slice, and wherein the slice includes a first region and a second region; 
 decoding sample adaptive offset (SAO) filter parameters from a slice data portion of the bitstream for the first region and the second region by at least decoding a SAO filter type from the bitstream; 
 following decoding the SAO filter parameters and following decoding the SAO filter type, decoding data from the bitstream for the first region; 
 following decoding the data for the first region, decoding data from the bitstream for the second region; 
 applying SAO filtering to the first region according to the SAO filter parameters and according to the SAO filter type; and 
 applying SAO filtering to the second region according to the SAO filter parameters and according to the SAO filter type. 
 
     
     
       2. The method of  claim 1 ,
 wherein the first region is a first coding unit (CU), and 
 wherein the second region is a second CU. 
 
     
     
       3. The method of  claim 2 , further comprising prior to decoding SAO filter parameters for the first region and the second region, decoding slice header information associated with the slice. 
     
     
       4. The method of  claim 1 ,
 wherein the slice is divided into a coding tree unit (CTU), and 
 wherein the CTU comprises the first region and the second region. 
 
     
     
       5. The method of  claim 1 , further comprising displaying the picture by a light emitting diode display. 
     
     
       6. The method of  claim 1 , further comprising displaying the picture by a liquid crystal display. 
     
     
       7. The method of  claim 1 ,
 wherein a value of the SAO filter type indicates band offset, 
 wherein applying the SAO filtering to the first region includes band-offset filtering the first region, and 
 wherein applying the SAO filtering to the second region includes band-offset filtering the second region. 
 
     
     
       8. The method of  claim 1 ,
 wherein a value of the SAO filter type indicates edge offset, 
 wherein applying the SAO filtering to the first region includes edge-offset filtering the first region, and 
 wherein applying the SAO filtering to the second region includes edge-offset filtering the second region. 
 
     
     
       9. A system comprising:
 a receiver configured to receive a bitstream representing a picture, wherein the picture includes a slice, and wherein the slice includes a first region and a second region; and 
 a video decoder coupled to the receiver, the video decoder configured to:
 decode sample adaptive offset (SAO) filter parameters from a slice data portion of the bitstream for the first region and the second region by at least decoding a SAO filter type from the bitstream; 
 following decoding the SAO filter parameters and following decoding the SAO filter type, decode data from the bitstream for the first region; 
 following decoding the data for the first region, decode data from the bitstream for the second region; 
 apply SAO filtering to the first region according to the SAO filter parameters; and 
 apply SAO filtering to the second region according to the SAO filter parameters. 
 
 
     
     
       10. The system of  claim 9 ,
 wherein the first region is a first coding unit (CU), and 
 wherein the second region is a second CU. 
 
     
     
       11. The system of  claim 10 , wherein the video decoder is further configured to decode slice header information associated with the slice prior to decoding SAO filter parameters for the first region and the second region. 
     
     
       12. The system of  claim 9 ,
 wherein the slice is divided into a coding tree unit (CTU), and 
 wherein the CTU comprises the first region and the second region. 
 
     
     
       13. The system of  claim 9 ,
 wherein a value of the SAO filter type indicates band offset, 
 wherein to apply the SAO filtering to the first region, the video decoder is configured to band-offset filter the first region, and 
 wherein to apply the SAO filtering to the second region, the video decoder is configured to band-offset filter the second region. 
 
     
     
       14. The system of  claim 9 ,
 wherein a value of the SAO filter type indicates edge offset, 
 wherein to apply the SAO filtering to the first region, the video decoder is configured to edge-offset filter the first region, and 
 wherein to apply the SAO filtering to the second region, the video decoder is configured to edge-offset filter the second region. 
 
     
     
       15. A system comprising:
 a receiver configured to receive a bitstream representing a picture, wherein the picture includes a slice, and wherein the slice includes a first region and a second region; 
 a video decoder coupled to the receiver, the video decoder configured to:
 decode sample adaptive offset (SAO) filter parameters from a slice data portion of the bitstream for the first region and the second region by at least decoding a SAO filter type from the bitstream; 
 following decoding the SAO filter parameters and following decoding the SAO filter type, decode data from the bitstream for the first region; 
 following decoding the data for the first region, decode data from the bitstream for the second region; 
 apply SAO filtering to the first region according to the SAO filter parameters and according to the SAO filter type; and 
 apply SAO filtering to the second region according to the SAO filter parameters and according to the SAO filter type; and 
 
 a display coupled to the video decoder, the display configured to display the picture. 
 
     
     
       16. The system of  claim 15 ,
 wherein the first region is a first coding unit (CU), and 
 wherein the second region is a second CU. 
 
     
     
       17. The system of  claim 16 , wherein the video decoder is further configured to decode slice header information associated with the slice prior to decoding SAO filter parameters for the first region and the second region. 
     
     
       18. The system of  claim 15 ,
 wherein the slice is divided into a coding tree unit (CTU), and 
 wherein the CTU comprises the first region and the second region. 
 
     
     
       19. The system of  claim 15 , wherein the display is a light emitting diode display configured to display the picture. 
     
     
       20. The system of  claim 15 , wherein the display is a liquid crystal display configured to display the picture.